Golf equipment manufacturers currently spend a large amount of time and money on research and development related to better golf clubs and golf balls. Their innovation has led to the development of golf clubs and balls with a wide range of performance characteristics to account for many different types of golfers. Golf clubs may have varying shaft lengths or stiffness. Golf clubs may be manipulated to have different head characteristics, such as loft or lie angle. They may even be manufactured with various combinations of materials in order to attain a specific coefficient of restitution (COR).
Similarly, golf balls have been developed and researched in a similar manner. Golf balls may have solid cores, semi-solid cores, or even fluid cores. They may be manufactured using injection molding processes or they may use a winding process. Even the covers have been manipulated to have a desired number of dimples or dimple arrangements, which aid in increasing or decreasing the lift and drag coefficients of the ball.
The innovations and efforts expended to produce optimal golf equipment, with specifications that meet the requirements set by professional golf associations, are aimed at providing golfers with the best chances of success. However, once a club and ball leave a manufacturer, the performance of the equipment depends largely on the technique and skill of an individual player. Thus, even the most advanced equipment may not be able to correct or fully compensate for flaws in a player's swing.
Many methods and devices have been developed in order to assist players in obtaining an optimal swing. These methods typically consist of acquiring images of a player swinging a golf club and making contact with a golf ball. In a most rudimentary system, photographs of a player's swing, possibly from different angles, may assist a player in correcting their swing. In more advanced systems, a club and ball may be tagged using a set of markers. In combination with a camera system, this can be a powerful tool for analyzing the swing of a player. Typically, the markers placed on the equipment are selected to create a high contrast on the images of the swing captured by the camera. In one example, the markers may be black dots on the surface of a white ball. A strobe fired at the ball during impact captures the black dots on a high contrast white background. The use of black dots, however, may not generate sufficient contrast to allow such a system to be used in an outdoor environment.
As a result, there have been improvements in the types of markers used in more advanced systems that can generate a higher contrast image that is possible with black dots. Two examples of markers in this category are retroreflective markers and fluorescent markers. Retroreflective markers may be manufactured using a variety of materials. These markers may then be placed onto golf equipment. Retroreflective markers are typically used because they return more light to a source than a white diffuse surface. This is because retroreflective markers are designed to reflect a large percentage of concentrated light as a narrow beam back to light source. This is in contrast to a white diffuse surface that reflects light in all directions. Examples of the use of retroreflective markers in monitoring a player's golf swing may be found in U.S. Pat. Nos. 4,158,853, 6,488,591 B1, and 5,471,383, the entireties of which are incorporated herein by reference thereto.
Fluorescent markers are also employed to analyze a player's golf swing. Fluorescent markers may also be manufactured using a variety of materials. However, in contrast to other types of markers, fluorescent markers only reflect light within a range of a desired wavelength. Therefore, when white light hits a fluorescent marker, a portion of the spectrum of the light will excite the fluorescent marker to only return light within a certain wavelength range. Fluorescent markers also return more light to a source than a white diffuse marker filtered at the emission wavelength. Examples of these types of markers, in combination with camera systems and filters, are described in U.S. Patent Application No. 2002/0173367, Gobush et al., the entireties of which are incorporated herein by reference thereto.
Typically, prior camera systems utilized only one type of marker for the objects being monitored. In other words, prior systems typically did not combine different markers. When multiple types of markers have been used, the monitoring systems essentially used two separate camera systems to capture images of the different markers. U.S. Patent Application No. 2002/0155896, for instance, uses two sets of two cameras to capture images of the club and images of the ball. Thus, the monitoring resulted in a complex event scene.
There have been other improvements to swing analysis systems. For instance, prior camera systems that acquire images typically encounter problems with noise and unwanted artifacts. Newer digital cameras typically employ a shutter and a CCD, among other components, to acquire an image. The CCD may be selectively activated and deactivated to acquire an image. This typically reduces the noise and artifacts that are included in an image. However, in many imaging systems that are used to acquire images of a player's swing and/or contact with a golf ball, ambient light can distort the image or captured images and reduce the accuracy and prevents an accurate analysis of a players swing.
A continuing need exists for an apparatus and method for accurately and consistently analyzing a golf players swing and the resulting flight characteristics of a golf ball.